Master of Science (M.Sc.) Theses and Dissertations
Permanent URI for this collection
Browse
Recent Submissions
- ItemOpen AccessComparative assessment of plant-based extracts and synthetic insecticides on the growth, yield and proximate composition of cowpea (Vigna unguiculata L. Walp)(Institute of Ecology and Environmental Studies, Faculty of Science, Obafemi Awolowo University., 2022) FOYINSOLAMI Ebunoluwa AdebayoThis study assessed the effect of plant-based and synthetic insecticides application on the growth response and yield of cowpea. It also investigated the effects of the insecticides application on the biomass, grain yield and proximate composition of cowpea grains produced. These were with a view to providing information on the use of plant-based extracts on quantity and quality of cowpea grains. The experiment was conducted on a vacant land measuring 11.75 m x 7.50 m behind the Institute of Ecology and Environmental Studies, Obafemi Awolowo University, Ile-Ife. Viable seeds of Ife-brown cultivar of cowpea were purchased from the Institute of Agricultural Research and Training, Ibadan. The experimental location was cleared manually two times using a cutlass and hand-held hoe. The experiment consisted of four treatments which were: extracts of three plant-based (Azadirachta indica, Tithonia diversifolia, Chromolaena odorata) and cypermethrin that served as control. The extracts of fresh shoots of A. indica, T. diversifolia, and C. odorata were separately prepared using standard method. The experiment was made up of 12 plots, each measuring 1.5 m x 2.0 m and the plots were arranged in a randomized complete block design. Four seeds per stand were sown using 50 cm x 30 cm spacing and seedlings thinned to 2 stands per hole at 2 weeks after sowing (WAS). The plots were weeded at 3 and 6 WAS. The cowpea stands were sprayed with plant-based and cypermethrin using the rates 100 g/L/plot and 15 mL/L/plot respectively at 5, 6, 7 and 8 WAS. Growth parameters such as plant height, number of leaves and stem girth were measured bi-weekly from 2 to 8 WAS and extent of leaf damage at 7 and 8 WAS. Tagged cowpea stands were carefully uprooted at 10 WAS to determine the total biomass yield. Cowpea pods were harvested when the pods turned yellow at 10 WAS and threshed. Proximate composition of cowpea grains (crude protein, ash, fibre, carbohydrate, fat and dry matter), and post-cropped soil analyses were carried out using standard methods. Data obtained were subjected to analysis of variance and their treatment means were separated using Tukey’s multiple comparison test at p < 0.05. The results showed that pH of the pre-cropped soil was 6.94 and soil texture was loamy sand. Organic carbon and total nitrogen were 0.64 and 5.82 g/kg, respectively and these values reduced to between 13 and 30% across the treatment plots for the post-cropped soil. The growth parameters; height (cm), number of leaves and stem girth (cm) at 6 WAS were: 23.06 ± 0.86, 55.29 ± 4.59 and 1.58 ± 0.05 for A. indica; 24.15 ± 0.75, 57.58 ± 3.94 and 1.69 ± 0.06 for T. diversifolia; 21.76 ± 0.68, 48.38 ± 2.15 and 1.55 ± 0.05 for C. odorata; and 21.99 ± 1.18, 45.26 ± 3.45 and 1.46 ± 0.07 for cypermethrin, respectively. Also, the grain yield of cowpea with cypermethrin, 1.08 t/ha was significantly (p < 0.05) higher than the best plant-based insecticide, T. diversifolia. Cowpea grains obtained with T. diversifolia and C. odorata had comparable and high values of crude protein (29.7%, 28.3%) and fibre (6.1%, 6.5%) respectively. The study concluded that T. diversifolia compared favourably with cypermethrin, in terms of grain yield of cowpea, whereas T. diversifolia and C. odorata gave higher proximate composition of cowpea.
- ItemOpen AccessADEBAYO E .B (2022) Comparative assessment of plant-based extracts and synthetic insecticides on the growth, yield and proximate composition of cowpea (vigna unguiculata l. walp) institute of ecology and environmental studies, Faculty of Science, Obafemi Awolowo University.(Institute of ecology and environmental studies, Faculty of Science, Obafemi Awolowo University., 2022) FOYINSOLAMI Ebunoluwa AdebayoThis study assessed the effect of plant-based and synthetic insecticides application on the growth response and yield of cowpea. It also investigated the effects of the insecticides application on the biomass, grain yield and proximate composition of cowpea grains produced. These were with a view to providing information on the use of plant-based extracts on quantity and quality of cowpea grains. The experiment was conducted on a vacant land measuring 11.75 m x 7.50 m behind the Institute of Ecology and Environmental Studies, Obafemi Awolowo University, Ile-Ife. Viable seeds of Ife-brown cultivar of cowpea were purchased from the Institute of Agricultural Research and Training, Ibadan. The experimental location was cleared manually two times using a cutlass and hand-held hoe. The experiment consisted of four treatments which were: extracts of three plant-based (Azadirachta indica, Tithonia diversifolia, Chromolaena odorata) and cypermethrin that served as control. The extracts of fresh shoots of A. indica, T. diversifolia, and C. odorata were separately prepared using standard method. The experiment was made up of 12 plots, each measuring 1.5 m x 2.0 m and the plots were arranged in a randomized complete block design. Four seeds per stand were sown using 50 cm x 30 cm spacing and seedlings thinned to 2 stands per hole at 2 weeks after sowing (WAS). The plots were weeded at 3 and 6 WAS. The cowpea stands were sprayed with plant-based and cypermethrin using the rates 100 g/L/plot and 15 mL/L/plot respectively at 5, 6, 7 and 8 WAS. Growth parameters such as plant height, number of leaves and stem girth were measured bi-weekly from 2 to 8 WAS and extent of leaf damage at 7 and 8 WAS. Tagged cowpea stands were carefully uprooted at 10 WAS to determine the total biomass yield. Cowpea pods were harvested when the pods turned yellow at 10 WAS and threshed. Proximate composition of cowpea grains (crude protein, ash, fibre, carbohydrate, fat and dry matter), preand post-cropped soil analyses were carried out using standard methods. Data obtained were subjected to analysis of variance and their treatment means were separated using Tukey’s multiple comparison test at p < 0.05. The results showed that pH of the pre-cropped soil was 6.94 and soil texture was loamy sand. Organic carbon and total nitrogen were 0.64 and 5.82 g/kg, respectively and these values reduced to between 13 and 30% across the treatment plots for the post-cropped soil. The growth parameters; height (cm), number of leaves and stem girth (cm) at 6 WAS were: 23.06 ± 0.86, 55.29 ± 4.59 and 1.58 ± 0.05 for A. indica; 24.15 ± 0.75, 57.58 ± 3.94 and 1.69 ± 0.06 for T. diversifolia; 21.76 ± 0.68, 48.38 ± 2.15 and 1.55 ± 0.05 for C. odorata; and 21.99 ± 1.18, 45.26 ± 3.45 and 1.46 ± 0.07 for cypermethrin, respectively. Also, the grain yield of cowpea with cypermethrin, 1.08 t/ha was significantly (p < 0.05) higher than the best plant-based insecticide, T. diversifolia. Cowpea grains obtained with T. diversifolia and C. odorata had comparable and high values of crude protein (29.7%, 28.3%) and fibre (6.1%, 6.5%) respectively. The study concluded that T. diversifolia compared favourably with cypermethrin, in terms of grain yield of cowpea, whereas T. diversifolia and C. odorata gave higher proximate composition of cowpea.
- ItemOpen AccessEvaluation of insecticidal activity of pteris ensiformis (Burn.F.) against cowpea weevil, callosobruchus maculatus (Fabricius)(Department of Biochemistry, Faculty of Science , Obafemi Awolowo University Ile Ife,Nigeria., 2023) Gedia, ObanaThis study investigated the toxicity bioassay of Pteris ensiformis leaf extracts against Callosobruchus maculatus. It assessed the oviposition and adult emergency effect of the most potent extract; as well as the sublethal effect of the most potent extract on some biochemical metabolites and on the neurotransmitting, detoxifying and antioxidant enzymes in C. maculatus and profiling the constituents of the extract using spectroscopic technique. These were with a view to providing aninformation on the insecticidal potential of Pteris ensiformis leaf on C. maculatus and the constituents responsible for this property. Fresh leaves of both sterile and fertile P. ensiformis were harvested and separately air-dried and milled into fine powder with the aid of an electrical grinder. The powdered samples (100 g) of sterile and fertile P. ensiformis leaves were soaked in 300 mL of 80% ethanol and n-hexane separately at room temperature for 72 h. Each sample was then filtered after 72 h through Whatman filter paper and the filtrates were concentrat(separately) on a rotary evaporator to give the fertile ethanolic (FE), fertile hexane (FH), sterile ethanolic (SE) and sterile hexane (SH) crude extracts of P. ensiformis leaf. Acute toxicity test was conducted by inhalation over a period of 24 h using five serial concentrations (0, 1.25, 2.5, 5 and 10 mg/mL) of each of the FE, FH, SE and SH extract on filter papers using standard method. Antioviposition test as well as repellency against the weevils were carried out on each of the extracts according to standard methods. Compared to others, FE showed highest mortality, anti-oviposition and repellency activities against C. maculatus. Thus, FE LC50 was determined using probit analysis and its sub-acute toxicity study at 80%, 40% and 20% of the LC50 was conducted for 6, 12, 18 and 24 h exposure periods. The tested insects at each exposure period were homogenized in phosphate buffer and the homogenate was assayed for the following biochemical parameters: alkaline phosphatase (ALP), lactate dehydrogenase (LDH), reduced glutathione (GSH), glutathione transferase (GST), superoxide dismutase (SOD), acetylcholinesterase (AChE), acid phosphatase (ACP), glycogen and total protein. Also, the constituents of fertile P. ensiformis ethanolic leaf extract was profiled via GC-MS analysis. Analysis of data were carried out using GraphPad Prism, Statistical Analysis Software (SAS), Trimmed Spearman-Karber (TSK) program (Probit analysis), Turkey Post Test (GraphPad Software, San Diego, CA, USA). The difference were considered to be significant if p ˂ 0.05. The results indicated 11.14 mg/mL as the LC50 value for fertile P. ensiformis ethanolic leaf extract. The result further revealed different patterns of inhibition (6 and 12 hours; p ˂ 0.05) and increases (18 and 24 hours; p< 0.05) in the activities of C. maculatus ALP, LDH, GSH, and AChE (p ˂ 0.05). Additionally, at all the exposure periods, GST activity was significantly stimulated while SOD activity was inhibited. Moreover, ACP activity (p ˂ 0.05) was consistently inhibited while glycogen and protein levels increased significantly at all the exposure periods. A total of 21 compounds were identified in fertile ethanolic leaf extract of P. ensiformis with four of the components (Cis-11-Hexadecenal, Octadecanal, Ethyl 9-hexadecenoate and nHexadecanoic acid) constituting 69.17% of the total extract. The study concluded that leaves of P. ensiformis (especially sporophylls) possess insecticidal properties that could be employed in the prevention of storage infestation of cowpeas.
- ItemOpen AccessEvaluation of Insecticidal Activity of Pteris Ensiformis (burn.f.) Against Cowpea Weevii, Callosobruches Maculatus (Fabricius).(Department of Biochemistry and Molecular Biology, Faculty of Science, Obafemi Awolowo University., 2023) OBANA GiediaThis study investigated the toxicity bioassay of Pteris ensiformis leaf extracts against Callosobruchus maculatus. It assessed the oviposition and adult emergency effect of the most potent extract; as well as the sublethal effect of the most potent extract on some biochemical metabolites and on the neurotransmitting, detoxifying and antioxidant enzymes in C. maculatus and profiling the constituents of the extract using spectroscopic technique. These were with a view to providing an information on the insecticidal potential of Pteris ensiformis leaf on C. maculatus and the constituents responsible for this property. Fresh leaves of both sterile and fertile P. ensiformis were harvested and separately air-dried and milled into fine powder with the aid of an electrical grinder. The powdered samples (100 g) of sterile and fertile P. ensiformis leaves were soaked in 300 mL of 80% ethanol and n-hexane separately at room temperature for 72 h. Each sample was then filtered after 72 h through Whatman filter paper and the filtrates were concentrat(separately) on a rotary evaporator to give the fertile ethanolic (FE), fertile hexane (FH), sterile ethanolic (SE) and sterile hexane (SH) crude extracts of P. ensiformis leaf. Acute toxicity test was conducted by inhalation over a period of 24 h using five serial concentrations (0, 1.25, 2.5, 5 and 10 mg/mL) of each of the FE, FH, SE and SH extract on filter papers using standard method. Anti-oviposition test as well as repellency against the weevils were carried out on each of the extracts according to standard methods. Compared to others, FE showed highest mortality, anti-oviposition and repellency activities against C. maculatus. Thus, FE LC50 was determined using probit analysis and its sub-acute toxicity study at 80%, 40% and 20% of the LC50 was conducted for 6, 12, 18 and 24 h exposure periods. The tested insects at each exposure period were homogenized inphosphate buffer and the homogenate was assayed for the following biochemical parameters: alkaline phosphatase (ALP), lactate dehydrogenase (LDH), reduced glutathione (GSH), glutathione transferase (GST), superoxide dismutase (SOD), acetylcholinesterase (AChE), acid phosphatase (ACP), glycogen and total protein. Also, the constituents of fertile P. ensiformis ethanolic leaf extract was profiled via GC-MS analysis. Analysis of data were carried out using GraphPad Prism, Statistical Analysis Software (SAS), Trimmed Spearman-Karber (TSK) program (Probit analysis), Turkey Post Test (GraphPad Software, San Diego, CA, USA). The difference weres considered to be significant if p ˂ 0.05. The results indicated 11.14 mg/mL as the LC50 value for fertile P. ensiformis ethanolic leaf extract. The result further revealed different patterns of inhibition (6 and 12 hours; p ˂ 0.05) and increases (18 and 24 hours; p< 0.05) in the activities of C. maculatus ALP, LDH, GSH, and AChE (p ˂ 0.05). Additionally, at all the exposure periods, GST activity was significantly stimulated while SOD activity was inhibited. Moreover, ACP activity (p ˂ 0.05) was consistently inhibited while glycogen and protein levels increased significantly at all the exposure periods. A total of 21 compounds were identified in fertile ethanolic leaf extract of P. ensiformis with four of the components (Cis-11-Hexadecenal, Octadecanal, Ethyl 9-hexadecenoate and n-Hexadecanoic acid) constituting 69.17% of the total extract. The study concluded that leaves of P. ensiformis (especially sporophylls) possess insecticidal properties that could be employed in the prevention of storage infestation of cowpeas.
- ItemOpen AccessAssessment of polyethylene Terephthalate Waste Carbon and periwinkle Shells-based Chitosan as Adsorbent for Trichloroacetic Acid Removal from Water(Department of Institute of Ecology and environmental Studies, Faculty of Science, Obafemi Awolowo University., 2022) BABASANMI, Oluwole AbioyeThe study determined the physicochemical parameters and trichloroacetic acid concentrations of the water samples before and after conventional treatment at the Obafemi Awolowo University, Ile-Ife water treatment plant. It also investigated the adsorption efficiencies of chitosan modified and unmodified adsorbent prepared from polyethylene terephthalate waste and periwinkle shells for the removal of trichloroacetic acids in the water samples. The study further compared the adsorption efficiencies of commercially available activated carbon with the chitosan modified and unmodified adsorbents. These were with a view to providing information on the adsorption efficiencies of polyethylene terephthalate waste carbon and periwinkle shells-based chitosan with commercially available activated carbon for the removal of trichloroacetic acid from water. Polyethylene terephthalate was obtained from the Obafemi Awolowo University Campus, while the periwinkle shell utilized for chitosan extraction was obtained from the Eket Main Market in AkwaIbom State. Caustic alkali produced from cocoa pod husk was used to activate the PET. The activated carbon was made by carbonizing the caustic alkali impregnated Polyethylene Terephthalate (PET) in a furnace at 500 °C for 1 hour. For elemental and surface morphology determinations, the activated carbon was evaluated using Energy Dispersive X-ray (EDX) and Scanning Electron Microscope (SEM). The Fourier Transform-Infrared (FT-IR) spectroscopic technique was used to determine the structural chemical functional groups in activated carbon. Chitosan was made by deproteinizing, demineralizing, decolourizing, and deacetylating the periwinkle shell. Using a UVvis Spectrophotometer, the level of trichloroacetic acid (TCA) in water samples was detected at 530 nm. Batch adsorption tests were conducted to investigate the removal of TCA under a variety of conditions, including the effect of concentration, adsorbent dosage, pH, and agitation time. Adsorption isotherms were calculated using experimental data from various initial TCA xxii concentrations. The adsorption kinetics were also used to identify a potential rate-limiting phase during the adsorption process. The results showed that the TCA levels were 0.9900 mg/L in raw water and 2.8900 mg/L in conventionally treated water. The PETAC, PETMAC, and commercial activated carbon (CAC) gave mean TCA concentrations of 0.1900±0.0000, 0.0900±0.0000 and 0.0900±0.0000 mg/L before adsorption and 0.1400±0.0707, 0.0900±0.0000 and 0.0000±0.0000 mg/L after adsorption on raw water and conventionally treated water, respectively. There was significant (p < 0.05) difference when raw and conventional treated water were subjected to the three adsorbents. The TCA removed by the two adsorbents (PETAC and PETMAC) required 4 minutes, 1.2 g/L adsorbent dose, and a pH of 9. At 4 minutes of contact time, the highest adsorption efficiencies were 80.286 and 98.286% for PETAC and PETMAC, respectively. The reusability efficiencies of PETAC and PETMAC were 78.4 and 82.4%, respectively. The PETAC with R2 = 0.9377, showed that Langmuir model best fit the TCA adsorption in the isotherm models. The PETMAC with R2 = 0.9986 indicated that the pseudo-second order fitted the kinetic data. This study concluded that activated PET carbon was effective to remove TCA from water supply and could be improved by adding chitosan.